3ds Max GMT Converter Help

I'm very new to all this (normally an engineering CAD designer) so bear with me. Just trying to export some tyres ive created using the gMotor textures in 3dsMax 8 and now trying to export them using the GMT converter. Its complaining that there are "No texture coordinates".

I've used "Planar from World XYZ" in the Coordinates menu of the gMotor Texture and also tried UVW mapping on the meshes. Can anyone advise how to add the texture coordinates?

I've also used jpeg images for all the gMotor textures as I can't figure out how to do an ordinary diffuse colour so if anyone could advise on this that'd be fab too.